Problem: Express your answer as a mixed number simplified to lowest terms. $17\dfrac{2}{20}-8\dfrac{1}{4} = {?}$
Solution: Simplify each fraction. $= {17\dfrac{1}{10}} - {8\dfrac{1}{4}}$ Find a common denominator for the fractions: $= {17\dfrac{2}{20}}-{8\dfrac{5}{20}}$ Convert ${17\dfrac{2}{20}}$ to ${16 + \dfrac{20}{20} + \dfrac{2}{20}}$ So the problem becomes: ${16\dfrac{22}{20}}-{8\dfrac{5}{20}}$ Separate the whole numbers from the fractional parts: $= {16} + {\dfrac{22}{20}} - {8} - {\dfrac{5}{20}}$ Bring the whole numbers together and the fractions together: $= {16} - {8} + {\dfrac{22}{20}} - {\dfrac{5}{20}}$ Subtract the whole numbers: $=8 + {\dfrac{22}{20}} - {\dfrac{5}{20}}$ Subtract the fractions: $= 8+\dfrac{17}{20}$ Combine the whole and fractional parts into a mixed number: $= 8\dfrac{17}{20}$